2011 Arctic Cat DVX 300 / 300 Utility ATV Service Manual, Page 31Get this manual
Measuring Piston Pin (Outside Diameter) and Piston-Pin Bore 1Measure the piston pin outside diameter at each end and in the centerIf measurement is not within specifications, the piston pin must be replaced
Installing Piston Rings
1Install ring expander (4) in the bottom groove of the piston; then install the thin oil rings (3) over the expander making sure the expander ends do not overlapStagger the end gaps of the upper and lower thin oil rings according to the illustrationNOTE: Note the direction of the exhaust side of the piston (5) for correct ring end gap orientation
ATV-1070
2Insert an inside dial indicator into the piston-pin boreThe diameter must not exceed specificationsTake two measurements to ensure accuracy
ATV-1085B
2Install the compression rings (1 and 2) so the letter on the top surface of each ring faces the dome of the pistonRotate the rings until the ring end gaps are on directly opposite sides of the piston according to the illustration